edwards



No. 62|,47I. N Patented MarN 2l, |899. W. R. EDWARDS S. F, BEEYDR. SWITCH FDR ALTERING SPEED AND DIRECTION- REVOLUTION 0F ELECTRIC MOTURS, c.

(Application led Sept` 6, 189B.)

I 2 Sheets-Sheet 9 la/ l H qi 7 -I/ l ,0 @ff/"@2036 5g 4 G/ ww?? )ad m W 1720*@ 71?506115.'

x/ aval-ammi amm/wk MMM ma www @hmm/ a f No. 62I,47I. Patented Mar. 2|, |899. W. R. EDWARDS & S. F. BEEVOR. SWITCH FOR ALTERING SPEED AND DIRECTION 0F REVOLUTION OF ELECTRIC MOTORS, 8m.

(Application Ied Sept. G, 1898.)

(No Model.)

y WILLIAM ROTVLAND EDTVARDS UNITED STATES- PATENT OFFICE.

AND SEPTIMUS FELIX BEEVOR, OF LONDON,

ENGLAND. Y

SWITCH FOR ALTERING SPEED AND DIRECTION OF REVOLUTION OF ELECTRIC MOTORS, ttc.

SPECIFICATION forming part of Letters Patent NO. 621,471, dated March 21, 1899.

Application filed September 6, 1898. Serial No. 690,328. (No model.)

in the art to which it appertains to make andl use the saine.

Our invention relates to electric motors used for propelling boats or for other purposes in which the current is supplied from electric accumulators orother batteries and in which it is required to drive the motor at different speeds and in either direction-as, for instance, (in the case of a boat,) at full speed or half-speed ahead, or at full speed or half-speed astern,-or to stop the motor altogether; and the objects of ourimprovementsy are, first, to attain the above requirements quickly and easily by the simple movement of a single handle, and, second, to reduce or prevent the injurious sparking of the parts by the contact of which the several changes are eliected. lVe attain these objects in the man- .ner and by the apparatus illustrated in the accompanying drawings, in which- Figure 1 is a plan, partly in section, showing the several contact-pieces and connections. Fig. 2 is a transversevertical section through the center of the apparatus. Fig. 3 is an end View. Fig. 4 is a diagrammatic plan illustrating the different contact-pieces, connections,electromotor,and batteries. Fig. 5 is a plan, and Fig. 6 a side View, shown partly broken off, of a modified method of operating the switch.

Similarletters and numerals refer to similar parts throughout the several iigures.

In eleetromotors of the kind described the speed of the motor is altered, as required, by grouping the cells of the batteries in different Ways. The direction of revolution of the motor is altered by reversing the electrical connection of the conductingwvire around either the armature or the field-magnet, but preferably the former. i

Supposing, for example, that two speeds (half-speed and full speed) in both directions are required, the arrangement and connections may be as follows, as illustrated in diagram inpFig. i: The battery is divided into two separate halves, which may be called B and B2, the positive and negative terminals of B being called 1 and 1, respectively, and those of B2 being called 2 and 2, respectively. The brushes connected with the armature of the motor M may be called A and A2, respectively, the terminals of the coils surrounding the field-1nagnet N being called E and F2, respectively.

For the different purposes required the va rions corresponding connections have to be made (by means of the switch) as follows:

For full speed ahead: l -1 to +2 2 to A2 A to F2 F to +1, (the two parts B and B2 of the battery being therefore arranged in series.)

For half-speed ahead:

+1 and F to +2 +2 and -1 to A2 A to F2,

(the two parts of the battery being in parF allel.)

For full speed astern: -1 to +2 2 to A' A2 to F2 F' to +1. For half-speed astern:

+1 and F to +2 -2and .-1v to A/ A2 to F2.

ICO

the brushes or equivalents c c c, by which the several contacts are made) is shown at d, somewhat nearer the right hand of the board than the center, and the several contactpieces e c7 c'X c, upon which the brushes o upon the lower side of the switch-arm l; press, are arranged, with their connections, upon the lower board or base g in the following manner:

The several coutact-piecese' e2 c7 and c'X @2X @7X are all curved concentric with the center (Z of the switch-arm, but at different distances from the center, so as to form six semicircular paths, each of which is not contin uous,but is formed as follows, (it being understood in this description that the curved contact-plates above the line a y inthe drawsemicircle through which the switch-arm l) travels, those below the line also occupying about one-third, and the central space between the two groups being left vacant, so that when the switch-arm is placed, as shown at b in Fig; l, above this space, corresponding with the horizontal line a; y, the motor is at rest. Taking the upper half first, the first contact-plate c, adjoining or nearest the center upon which the switch-arm turns, is in electrical connection with F2, (one terminal of the iield-magnet coil, Fig. Ll.) The next (second) curved concentric contact-piece c?, at a sui'licient radial distance from the central one, occupies about one-third of the semicircle and is in electrical connection through the conductor k2 and the lower contact-piece with A, one of the armaturebrushes. (See Fig. l.) The next (third) contact-piece ci also occupies the same angular space (one-third of the semicircle) and is in connection with the terminal 7L', Fig. l, and through it with A2, the other armaturebrush. (See Fig. l.) The next (fourth) contact-piece c4 occupies a similar angularspace and is in connection directly or through the conductor k" with the +2 pole of the second half B2 of the battery. (See Fie'. +L.) The next (fifth) outer contact-piece has its end adjoining the central vacant part of the semicircle in the same radial line as the other contact-pieces; but its other end extends to only about one-third of the circumferential length of the others. rlhe next (sixth) outer contactpieee eG has about one-third removed at the center, only its two ends remaining, and its higher end (or that nearest the top of the drawings) is in metallic connection through the conductor lt with the tifth or adjoining inner contact-piece e5 last described, both being in connection through the conductors L5 and LG and the terminal h3 with the -l pole of the first half B of the battery,Fig. At. The outer (seventh) contact-piece calso has about the terminal h6 with the +1 pole of the first p half B of the battery, Fig. 4. It will be understood that the concentric segments shown in Fig. i and the shaded segments in Fig. l represent the conducting contaet-pieeesover which the brushes of the switch pass to make contact, and the parts between them are of non conducting material, over which the brushes c, Figs. 2 and 3, pass between the contact-pieces. The metallic connections bctween the different conducting-segments c are shown in dotted lines L in Figs. l and l. They are arranged below the base g of the instrument, as seen in Figs. 2 and 3.

rlhe lower half of the semicircular set of contact-pieces, or that relating to the changes of current necessary for reversing the direction of revolution of the motor, is similar to the upper one as far as regards the angular length and position of the contact-pieces; but the connections are diiferent, as follows: The second contact-piece 02X is eonnccted,throu gh the conductor k3, with the third e3 on the upper half, and therefore, through the terminal 7L', with the armature-brush A2. The third contact-piece @3X is connected, through the conductor 7g2, with the second e? on the other side and through the terminal 7L with the other armature-brush A. The fourth @"X is connected by the conductor 7.7! with the Vfourth c" on the otherside through the terminal h2 and with the 2 pole of the B2 half of the battery, Fig. ft. The fifth contact-piece @5X is connected, by the conductor N, with the fifth c5 on the other side and also, through the conductor 7u, with the inner end of the sixth c"` and, through the terminal 7b3, with the l pole of the B' half ot' the battery. 'lhc outer or right-hand end of the sixth contact-piece cw( is connected, through the conductor k3, with the corresponding outer end of the sixth c" on the other side and also, through the conductor kg, with the inner end of the outermost (or seventh) contact-piece el, while both are connected, through the conductor kw and the terminal 7L", with the +2 pole of the B2 half of the battery. Finally, the outer end of the seventh contact piece @7X is connected, through the conductor L12, with the outer end of the corresponding seventh contact-piece c7 on the other side and also, through the couducting-wire l, (in the manner hereinafter.

described,) with the terminal r'" to the F terminal of the field-magnet coils, so that both contact-pieces c7 and @7X are connected with.

both this field magnet terminal F' and, through the terminal it, the battery-pole +1. The contact pieces or brushes c c2 t3 c* ce IOO IIO

on the lower side of the switch-arm l) are six 'in number and of suitable length. The inner one c' presses upon the contact-pieces c2 and c6X as the switch l) is turned. It is also in constantA connection with the inner contact-ring e through the metal arm l). The brushes c2 cS c4 press upon the contact-pieces e2 @23, c3 e, and e4 94X, respectively, as the switch is turned. They are in metallic connection with each other, but are insulated by insulating material 0 from the switch-arm l) and the other brushes. The brushes c5 and cG press upon the contact-pieces c5 @5X and e( ci, respectively. They are in metallic connection with each other, but are also insulated from the switch-arm l) and the other brushes. ln this way as the arm is moved to the different positions the brushes connect the different contact-pieces in the required way, as already described, the inner brush being always in metallic connection with the inner contact-piece c adjoining the central spindle d of the arm l). The brushes c may be solid or built up or laminated and fit into recesses in metal blocks p p, insulated from, but attached to, the switch-arm b, and they are formed or provided with springs which press them into sufficiently good electrical contact with the scveralcontact-pieces e belowl them. As, however, sparking may occur on the contactpieces when the brushes come in contact with or leave them, we prefer to entirely cut off electrical current through them except when the brushes are properly pressing upon the contact-pieces. This we do by means of a separate metal switch-arm which works in proper relation with that, b, already described, but which gradually completes the circuit (between +1 and F) when the swi-tch -brushes c have reached their proper position upon the contact-pieces c below and gradually breaks the circuit before the brushes have left the contact-pieces. For this purpose we arrange on the left-hand side of the apparatus, viewed from above, as described, a secondswitch, consisting of an arm in, turning upon (but insulated from) a center fa near one of its ends, which end o" is provided with a brush or contact-piece s in meg tallic contact with a curved contact-plate below, which is connected with the terminal F ofthe eldanagnet coil. (See Fig. 4.) The other or longer arm u of this switch-arm m is also provided with a brush or 'contact-piece t, which presses lin succession upon a series of separate fixed contact-pieces tu 'L02 w3 as the switch-arm m is moved through about a quar ter of a circle.

Vheu the switch-arm described is in a central position, (pointing, that is to say, directly to the center d of the main switch-arm first described,) the contact or brush Q2 upon its longer arm u rests upon a central fixed contact-piece fr, which is connected with a conducting-wire leading to and connected with -the outer orl seventh fixed contact-pieces e'r paratus first described, (see Fig. 4,) which contact-pieces are therefore connected,.

through the second switch-arm' m, (which forms an insulated conducting-bridge,) with the terminal F of the field-'magnet coil.

Assuming that a series of, say, three separate fixed contact-pieces w' w2 w3, as shown, are used, against which the brush 'u upon the longer arm u of the second switch presses in succession, as described, suitable resistances y p21/3 of the well-known kinds are arranged between w( and 102, 102 andv w3, and between 'w3 and the central one which is connected with F of the field-magnet, as described. If, therefore, the second switch m is in a position across the apparatus, with the brush on its longer arm resting upon the first w( of the contact-pieces, the current through the bridge has to pass through the whole of the resistances y' y2 p3 on its way to x, and as the switch m is moved around its longer arm u passes in succession over the other contactpieces w2 and w3, the resistance being gradually reduced until in its final posit-ion the resistances have all been cut out and the cnrrent passes' through fr, directly through the bridge, and through the contact t under the shorter-arm. The current is therefore grad ually (instead of suddenly) admitted to the circuit. A similar set of fixed contact-pieces wX, 102x, and 103x and resistances y'X, i 2X, and ySX (or the same resistances may be made use of) is arranged on the opposite side of the apparatus, so that if the movement of the switch-arm or bridge m is continued through another quarter of a circle the current is gradually cut off from (instead of being gradually supplied to) the circuit. During the other half of the revolution of the switch or bridge over the part marked .21, Fig. l, (if it is turned through a complete circle,) its longer arm is free from any contact. It only remains, therefore, to make au arrangement by which during the time that the current is thus entirely cut off from the bridge m the other switch-arm Zi is adj usted into the proper position, (according to the requirements of full speed ahead, half-speed ahead, full speed astern, and half-speed astern,) and when this has been done the continued movement of theA second switch or bridge m then admits the current through the proper connections to obtain the required result. In the same way when a modified result is required.the current is first gradually cut off, and the main switch is then moved into its new position and the current gradually readmitted through the newly-selected circuit. In order to effect this, we fix upon the spindle d, which carries the main switch, as shown in Figs. 2, 3, and 5, a disk 1 of considerable diameter, insu lated from the spindle d and having a series or radial slots or notches 2, 3, 4L, and 5 in its circumference, and upon the spindle n, which carries the second switch or bridge m, we fix a second disk or arm G, carryingapin 7, which engages with one or other of the slots 2, 3, et,

ICO

IIO

or 5, and (as the bridge m is turned around by a handle S) at each complete revolution moves the larger disk l and main switch-arm l) through a sufficient space to change the connections from one position to the next. The pin 7 is so arranged that when it is acting upon one of the slots and turning the main switch-arm Z) the current through the bridge m is cut oft, while after the pin 7 has left the slot the continued revolution of the handle 8 gradually admits the current through the bridge m and the main switch-arm ZJ in the way already described. lVhen further alteration is required, the handle S is again turned and the current is first gradually cut oti, and the pin '7 then engages with one of the notches and brings the main switch b into a fresh position, and after this is done the current is automatically readmitted.

Instead of the notched disk operated by a pin well-known equivalent devices may be made use of. For instance, a toothed wheel may be fixed upon the spindle of the main switch-arm, gearing with the pinion upon the spindle of the conducting-bridge- The pinion is provided with teeth upon only a part of its circumference, so that it only causes the revolution of the main switch-arm at the Same time when the current has been out olf, the remainder of the revolution of the handle leaving t-he larger-toothed wheel stationary while the current is being gradually admitted or cut oft.

A hand or pointer 9 is carried by the spindle CZ of the main switch-arm ZJ and shows the exact position of the latter. By the use of suitable gear the necessary movements of the second switch or bridge may be produced without a complete revolution of the handle. For this purpose the arrangement illustrated in Figs. 5 and t5 may be used. The handle 8 is carried upon a third spindle 10, which has iixed upon it atoothed wheel ll, gearing with a smaller pinion i2 upon the spindle n of the smaller switch. By this means the requisite number of revolutions of the wheel G and pin 7 to move the main switch through the required number of degrees of a circle can be eliected by a single revolution or by part of a revolution of the handle 8. A spring detent may be arranged, pressing against the notches in the disk or against other notches suitably arranged for the purpose, so that the position of the main switch-arm is prevented from being accidentally altered, but without preventing its revolution when required. This arrangement, which is not essential, is so obvious that it has not been illustrated.

XVe arrange a movable contact-plug in a suitable part oi` the conducting-wire circuitfor instance, at i3, Figs. l and i-which can be readily removed when desired, so as to prevent any tampering with the apparatus.

The number of different effective positions of the main switch-arm may be increased to any desired extent, the necessary connections for the corresponding circuits of the current being arranged accordingly.

The insulated cases containing the springbrushes can be readily removed when necessary to substitute fresh brushes.

Having fully described our invention, what we desire to claim and secure by Letters Patent isl. The combination, in a switch for altering the speed and direction of revolution of electric motors, of a spindle (Z turning in bearings in the frame u, g, switcharn1 b, carrying spring-brushes c', c2, c3, c, c5, c6, insulated from the switch-arm Z), concentric insulated contact-pieces e', e2, c3, e", e5, c6, c7, below the spring-brushes 0,011 one side ofthe central line :c y, concentric insulated contact-pieces 62X, 63X, 61X, 65X, c, 67X, below the spring-brushes c, but on the other side of the central line .T y, insulated conductors 7&2, 7e3, 7a", h5, LG, k7, 7g3, 7a, kw, 7c, k12, connecting the different concentric contact-pieces c e7, @2X 67X, and conducting-wires and terminals 7L, 7L', 7a2, h3, 714, and h, with the poles -l-l, 1, +2 and 2 of the two halves of the batteries B, B2, with the coils of the iieldmagnets at F', F2, and with the commutator-brushes A', A2, substantially as described.

The combination with the spindle (Y, switch-arm Z), insulated spring-brushes c c, concentric insulated contact-pieces c c7, and @2X 67X, insulated conductors 7a2 L12, and conducting-wires and terminals L- 7L, of the handle 8 on second spindle n carrying insulated bridge m, spring-brushes and fr, insulated concentric contact-pieces t, tlf, tu?, w3, ai, wX, 102x, 103x, resistances y', if, @/3, y/X, if, y, conductor Z between the contact-pieces .fr and 67X, and conductor from the contact-piece t to the terminal h5 and terminal F'- of the field-magnet coil, substantially as described.

In testimony whereof we have hereunto aiiixed our signatures in presence of two witncsses.

li'ilililill ROWLND EDWARDS. SHPTIMUS FELIX llllliVOll.

IOO 

